Hello everybody!I need your advice:I have recently made a sleeping bag that is warmer than anything on the market. It should also take up less space and be a bit lighter than the current warmest bags (at the moment it is not lighter but after a little time and effort i think it will be). I'm very new to mountaineering so don't really know if mountaineers would actually find it useful. Are sleeping bags warm enough already?

I am thinking about taking it to a mountaineering gear manufacturer, and asking for their help to manufacture these sleeping bags, but just thought I would ask you if you would actually use it first.

Climbers are interesting in anything that will reduce weight and bulk. A sleeping bag only needs to be just warm enough for the anticipated temperatures. This may be +40 F or - 40 F. My $0.02: put it in the hands of knowledgeable climbers who can give you their honest feedback. Dane1 http://www.summitpost.org/users/dane1/63774 on our little chat board here has more climbing experience than just about anybody and has a very influential blog: http://coldthistle.blogspot.com/. Gear manufactures listen to him for good reason. He has seen trends come and go and come back again. I bet if you sent him a sample he would tell you if what you have is worth pursuing.

First of all, this should have been posted in the "Gear" section rather than in "General." Secondly, there is no such thing as a "warmest" sleeping bag; there's only warmest for its weight and warmest for its volume. I'd have to guess that you mean warmest for its volume and, from what you say, the potential of warmest for its weight.

Sounds like you are talking about a bag insulated with nanogel or some other newfangled material. If that is the case, then the main concern would be durability - nobody is going to take a risk on it without knowing that it is durable. If you can get that issue in hand, the next issue whould be the cost/benefit ratio - does it give enough benefit to justify the cost. If the cost is less than down, it might have the cost/benefit issue licked; if not, it would have to offer significan advantage.

An aerogel sleeping bag would be very interesting in terms of loft (warmth) for the weight. Durability is one concern - mountaineering gear takes a lot of rough treatment. A particular kind of durability is important: compressibility. I frankly don't care that my synthetic-fill winter bag weighs a quarter-pound more than my down winter bag, I care that my down bag takes only a quarter as much space when stored in my backpack. (The synthetic bag nearly fills up my largest pack, leaving almost no room for such minor items as food.) You'd want it to compress easily, loft out fairly quickly without special effort, and remain compressed for weeks without losing loft (e.g., when travelling to a big mountain, you don't need the big bag 'til you get there.) A few hundred compression cycles would be a good test - that's like a few years of use.

Don't know what your manufacturing costs are, but you could charge a premium just based on the high-tech cachet of the material. To survive in the market, though, you'd have to also get the shell right. Got to be strong, light, not too slippery, water-resistant, ideally wind-resistant and breathable; come in the right shapes and sizes, etc. The fill is only one part. Then you've got to make sales... you might need a partner.

Several of us here on SP have contacts in the outdoor gear industry, if you're serious.

Dude, if you've got something that's better than the other stuff on the market, patent it before you go showing it to anybody. A manufacturer will look over your bag, say no thanks, and give his developers everything you told him.

Old Stephenson-Warmlite catalog has some info on sleeping bag theory you might find useful. Be aware the models in the catalog are not wearing clothes! (This is only part of the original catalog that had more technical info.)http://warmlight.net/cat-web.pdf